The latest LQM18JN series of chip inductors from Murata have been developed for near field communication (NFC) applications. The devices can overcome the inherent problems associated with previous NFC designs to offer a better, more consistent performance.
In recent years an increasing number of electronic devices such as smartphones have included NFC capability. NFC circuits utilise a chip inductor for impedance matching. However, due to the large currents that flow in an NFC matching circuit, the effect of magnetic saturation upon the inductor can seriously hinder the expected performance.
Murata’s LQM18JN series has been designed specifically for NFC matching circuits and is not easily impacted by magnetic saturation. In addition, its closed magnetic circuit configuration suppresses interference with surrounding components even at high mounting density, making it well suited for reducing the size of the NFC circuit. Small in size at 1.6L × 0.8W× 0.55mmH, and with a ±5 percent narrow deviation, they are also well suited for impedance matching.
Aimed for use in NFC modules mounted in devices such as smartphones, the range currently embraces three inductors. The 100nH rated LQM18JNR10J00 has a self-resonance frequency of 200MHz and a current rating of 650mA, the LQM18JNR12J00 is similarly rated at 120nH, 150MHz and 610mA, and finally the LQM18JNR16J00 is rated at 160Nh, 100MHz and 550mA. All three inductors share a Q rating of eight or more.